[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20200210193743.GE3416@kernel.org>
Date: Mon, 10 Feb 2020 16:37:43 -0300
From: Arnaldo Carvalho de Melo <arnaldo.melo@...il.com>
To: Jiri Olsa <jolsa@...hat.com>
Cc: Namhyung Kim <namhyung@...nel.org>,
LKML <linux-kernel@...r.kernel.org>,
linux-perf-users@...r.kernel.org
Subject: Re: [PATCH v2] tools lib api fs: Move cgroupsfs__mountpoint()
Em Tue, Jan 28, 2020 at 10:40:57AM +0100, Jiri Olsa escreveu:
> On Tue, Jan 28, 2020 at 09:49:40AM +0900, Namhyung Kim wrote:
> > Move it from tools/perf/util/cgroup.c as it can be used by other places.
> > Note that cgroup filesystem is different from others since it's usually
> > mounted separately (in v1) for each subsystem.
> >
> > I just copied the code with a little modification to pass a name of
> > subsystem and renamed it to follow other APIs.
> >
> > Suggested-by: Jiri Olsa <jolsa@...hat.com>
> > Signed-off-by: Namhyung Kim <namhyung@...nel.org>
>
> Acked-by: Jiri Olsa <jolsa@...hat.com>
Thanks, applied to perf/core.
- Arnaldo
> thanks,
> jirka
>
> > ---
> > * rename to cgroupfs__mountpoint()
> >
> > tools/lib/api/fs/Build | 1 +
> > tools/lib/api/fs/cgroup.c | 67 +++++++++++++++++++++++++++++++++++++++
> > tools/lib/api/fs/fs.h | 2 ++
> > tools/perf/util/cgroup.c | 63 ++----------------------------------
> > 4 files changed, 72 insertions(+), 61 deletions(-)
> > create mode 100644 tools/lib/api/fs/cgroup.c
> >
> > diff --git a/tools/lib/api/fs/Build b/tools/lib/api/fs/Build
> > index f4ed9629ae85..0f75b28654de 100644
> > --- a/tools/lib/api/fs/Build
> > +++ b/tools/lib/api/fs/Build
> > @@ -1,2 +1,3 @@
> > libapi-y += fs.o
> > libapi-y += tracing_path.o
> > +libapi-y += cgroup.o
> > diff --git a/tools/lib/api/fs/cgroup.c b/tools/lib/api/fs/cgroup.c
> > new file mode 100644
> > index 000000000000..c7e1cdaa36e1
> > --- /dev/null
> > +++ b/tools/lib/api/fs/cgroup.c
> > @@ -0,0 +1,67 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +#include <linux/stringify.h>
> > +#include <sys/types.h>
> > +#include <sys/stat.h>
> > +#include <fcntl.h>
> > +#include <stdio.h>
> > +#include <stdlib.h>
> > +#include <string.h>
> > +#include "fs.h"
> > +
> > +int cgroupfs__mountpoint(char *buf, size_t maxlen, const char *subsys)
> > +{
> > + FILE *fp;
> > + char mountpoint[PATH_MAX + 1], tokens[PATH_MAX + 1], type[PATH_MAX + 1];
> > + char path_v1[PATH_MAX + 1], path_v2[PATH_MAX + 2], *path;
> > + char *token, *saved_ptr = NULL;
> > +
> > + fp = fopen("/proc/mounts", "r");
> > + if (!fp)
> > + return -1;
> > +
> > + /*
> > + * in order to handle split hierarchy, we need to scan /proc/mounts
> > + * and inspect every cgroupfs mount point to find one that has
> > + * perf_event subsystem
> > + */
> > + path_v1[0] = '\0';
> > + path_v2[0] = '\0';
> > +
> > + while (fscanf(fp, "%*s %"__stringify(PATH_MAX)"s %"__stringify(PATH_MAX)"s %"
> > + __stringify(PATH_MAX)"s %*d %*d\n",
> > + mountpoint, type, tokens) == 3) {
> > +
> > + if (!path_v1[0] && !strcmp(type, "cgroup")) {
> > +
> > + token = strtok_r(tokens, ",", &saved_ptr);
> > +
> > + while (token != NULL) {
> > + if (subsys && !strcmp(token, subsys)) {
> > + strcpy(path_v1, mountpoint);
> > + break;
> > + }
> > + token = strtok_r(NULL, ",", &saved_ptr);
> > + }
> > + }
> > +
> > + if (!path_v2[0] && !strcmp(type, "cgroup2"))
> > + strcpy(path_v2, mountpoint);
> > +
> > + if (path_v1[0] && path_v2[0])
> > + break;
> > + }
> > + fclose(fp);
> > +
> > + if (path_v1[0])
> > + path = path_v1;
> > + else if (path_v2[0])
> > + path = path_v2;
> > + else
> > + return -1;
> > +
> > + if (strlen(path) < maxlen) {
> > + strcpy(buf, path);
> > + return 0;
> > + }
> > + return -1;
> > +}
> > diff --git a/tools/lib/api/fs/fs.h b/tools/lib/api/fs/fs.h
> > index 92d03b8396b1..07591ecbe39f 100644
> > --- a/tools/lib/api/fs/fs.h
> > +++ b/tools/lib/api/fs/fs.h
> > @@ -28,6 +28,8 @@ FS(bpf_fs)
> > #undef FS
> >
> >
> > +int cgroupfs__mountpoint(char *buf, size_t maxlen, const char *subsys);
> > +
> > int filename__read_int(const char *filename, int *value);
> > int filename__read_ull(const char *filename, unsigned long long *value);
> > int filename__read_xll(const char *filename, unsigned long long *value);
> > diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c
> > index 4881d4af3381..12e466d1ec3b 100644
> > --- a/tools/perf/util/cgroup.c
> > +++ b/tools/perf/util/cgroup.c
> > @@ -3,75 +3,16 @@
> > #include "evsel.h"
> > #include "cgroup.h"
> > #include "evlist.h"
> > -#include <linux/stringify.h>
> > #include <linux/zalloc.h>
> > #include <sys/types.h>
> > #include <sys/stat.h>
> > #include <fcntl.h>
> > #include <stdlib.h>
> > #include <string.h>
> > +#include <api/fs/fs.h>
> >
> > int nr_cgroups;
> >
> > -static int
> > -cgroupfs_find_mountpoint(char *buf, size_t maxlen)
> > -{
> > - FILE *fp;
> > - char mountpoint[PATH_MAX + 1], tokens[PATH_MAX + 1], type[PATH_MAX + 1];
> > - char path_v1[PATH_MAX + 1], path_v2[PATH_MAX + 2], *path;
> > - char *token, *saved_ptr = NULL;
> > -
> > - fp = fopen("/proc/mounts", "r");
> > - if (!fp)
> > - return -1;
> > -
> > - /*
> > - * in order to handle split hierarchy, we need to scan /proc/mounts
> > - * and inspect every cgroupfs mount point to find one that has
> > - * perf_event subsystem
> > - */
> > - path_v1[0] = '\0';
> > - path_v2[0] = '\0';
> > -
> > - while (fscanf(fp, "%*s %"__stringify(PATH_MAX)"s %"__stringify(PATH_MAX)"s %"
> > - __stringify(PATH_MAX)"s %*d %*d\n",
> > - mountpoint, type, tokens) == 3) {
> > -
> > - if (!path_v1[0] && !strcmp(type, "cgroup")) {
> > -
> > - token = strtok_r(tokens, ",", &saved_ptr);
> > -
> > - while (token != NULL) {
> > - if (!strcmp(token, "perf_event")) {
> > - strcpy(path_v1, mountpoint);
> > - break;
> > - }
> > - token = strtok_r(NULL, ",", &saved_ptr);
> > - }
> > - }
> > -
> > - if (!path_v2[0] && !strcmp(type, "cgroup2"))
> > - strcpy(path_v2, mountpoint);
> > -
> > - if (path_v1[0] && path_v2[0])
> > - break;
> > - }
> > - fclose(fp);
> > -
> > - if (path_v1[0])
> > - path = path_v1;
> > - else if (path_v2[0])
> > - path = path_v2;
> > - else
> > - return -1;
> > -
> > - if (strlen(path) < maxlen) {
> > - strcpy(buf, path);
> > - return 0;
> > - }
> > - return -1;
> > -}
> > -
> > static int open_cgroup(const char *name)
> > {
> > char path[PATH_MAX + 1];
> > @@ -79,7 +20,7 @@ static int open_cgroup(const char *name)
> > int fd;
> >
> >
> > - if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1))
> > + if (cgroupfs__mountpoint(mnt, PATH_MAX + 1, "perf_event"))
> > return -1;
> >
> > scnprintf(path, PATH_MAX, "%s/%s", mnt, name);
> > --
> > 2.25.0.341.g760bfbb309-goog
> >
>
--
- Arnaldo
Powered by blists - more mailing lists